Corrugated packing sheet



Feb. 9, 1954 PERRY 2,668,786

CORRUGATED PACKING SHEET Filed June 22, 1949 INVENTOR.

EUGENE Lv PERRY ATTORNEYS Patented Feb. 9, 1954 CORRUGATED PACKING SHEETEugene L. Perry, Bloomfield, N. J.; Helen M. Swope and Grace Gubernator,executrices of said Eugene L. Perry, deceased, assignors, by mesneassignments, to Packaging Materials Corp., Providence, R. L, acorporation of Rhode Island Application June 22, 1949, Serial No.100,702

1 Claim. 1

This application is directed to an improvement The object of the presentinvention is to provide a corrugated packing sheet made of pulp which isflexible for folding both along lines parallel with the corrugations andalso along lines transverse to the corrugations, to thereby facilitatefolding the paper around cylindrical articles such, for example, asglass jars con- .3 taining pharmaceutical preparations, and then foldingthe projecting end portions of the wrapping sheet down over the ends ofthe jars to protect the jar in all directions from breakage.

In the accompanying drawings Fig. 1 is a perspective view on an enlargedscale showing a portion of a sheet of paper manufactured in accordancewith my new method;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig. 3 is a diagrammatic sectional View showing the essential parts ofthe apparatus disclosed in my former patent with the addition of theparts for providing the transverse scores in the freshly formed sheet;and

Fig. 4 is a detail view showing the scoring roll in plan view.

Referring to the drawings, my improved packing sheet is formed directlyfrom pulp on a suction drum having its surface formed with corrugationsof any desired contour, but preferably somewhat fiatter than shown in myprevious patent. The cylinder is covered with an underlying coarsescreen and a superimposed fine screen of the construction shown in myprior patent and therefore not shown in detail herein. The pulp issupplied to the cylinder I from a flow box indicated at 2 which may beof the construction shown in my former patent. At the forward end of theflow box in the direction of rotation of the cylinder is a metering roll3 for regulating the amount of pulp deposited on the cylinder.

In the drawing the contour of the corrugations is such that the groovesin the cylinder in which the corrugations are formed are substantiallyfilled with the pulp as the cylinder passes through the flow box, sothat when the water is drawn from the pulp through the suction holes inthe bottom of the grooves the exposed face of the sheet, that is, theface opposite the corrugations, will have depressions on the other sidebut of a very slight depth compared with the height of the corrugations.In other words, the corrugations on the face of the paper are composedthroughout substantially their depth of loosely matted fibres which havebeen compressed somewhat by the suction extraction of the Water, butwhich have not been compressed by the metering roller or by the facingroller 4 which will now be described.

This facing roller is of the construction shown in my prior patent andis mounted in a flow box from which it picks up a layer of pulp throughthe suction supplied from a suction port 6. This roller is of smoothcylindrical contour and is covered with coarse and fine screens in themanner described in my prior patent. The periphery of the facing rollerlies adjacent to the periphery of the corrugating roller and is spacedfrom the crowns of the corrugations on the cylinder to an extentcorresponding to the desired thickness of the sheet between thecorrugations.

The layer of pulp picked up by the facing roller is transferred to thesurface of the sheet formed on the cylinder at a time when both sheetsare quite wet, and the suction through the surface of the cylinder drawsthe soft sheet of wet pulp on the facing roller down against the sheetof pulp so that the sheet formed on the facing roller assumes thecontour of the exposed face of the corrugated sheet and the contactingfibres are so intermeshed by the suction that there is no significantline of demarcation between the pulp applied by the facing roller andthe pulp sheet formed on the cylin der. The transfer of the pulp fromthe facing roller is aided by a discharge of compressed air from thecompressed air pipe I, and the suction in the cylinder draws the pulpfrom the facing roller down somewhat into the corrugations while at thesame time the portions between the corrugations are compressed betweenthe crowns of the corrugations and the surface of the facing roller.

The composite sheet has the cross sectional contour shown in Fig. 1,wherein A indicates the corrugations and B the spaces between thecorrugations. In the spaces B there is no discernible line ofdemarcation between the layer of pulp picked up on the cylinder and thelayer transferred from the facing roller. The same is true of thecorrugations A except that the fibres at both surfaces of thecorrugations are somewhat more compressed than in the intermediate partand the whole surface on both sides carries the impression of the finescreen forming the surface of both the cylinder and the finishingroller.

The composite sheet formed as above described is discharged from thecylinder by compressed air from a compressed air pipe 8 onto a dryingbelt 9 underlying the cylinder. At a point somewhat beyond the point atwhich the sheet is received by the dryingbelt where the pulp ispartially dried butis still soft enough to receive impressions, the'belt isdis'con'tinued'and a pair of scoring rolls l and II areintroduced which serve to impress into the corrugations a series ofparallel score lines such as illustrated at fl2 in Fig. 1, these scorelines being of a depth of approximately one-half the height of 'thecorrugations above the surface of the 'iiaperfhetween the corrugations.The upper scoringiroller is preferably mounted in an adjustable hearing1S6 that-[the depth of the score lines may be adjusted for sheets ofdiiferent thickness. Immediately beyond the scoring rollers anotherdrying belt-43 is provided to support the sheet until it is fully dried.V p v It desired, the facing 'roller with its pulp supply maybe"timittedalt'ogether, in which case the iliga'ted' sheet Will havesubstantially the same 'con'touroflboth'surfaces, as illustrated, butwill "1 not "be'coriipressed to the same extent between thecorrugations. Also, if desired, the 'facing rol ler may be empl'oyedbut'Without supplying the flovv'bbx'itithpulp; When so used the facing"rolleractsas a press roller to give a Wire finish "'trfthe b ack'of thesheet fiand'oompress the pulp "bettveenthe corrugations, but Without anysubsta'fitial compression where the corrugation are 'biifltu'pbn theCylinder. I I have sho'wflmy'nev'v packing sheet in its pre-"reread-"farm and also illustrated a preferred method and apharatusfformaking the same; but i itis"to'beunderstood thatthe invention is not""liinited"to thedetails hereina-b'ove described but sheetbfflt edpulphaving corrugations built up of substantially uncompressed pulp withintervening portions pressed to greater density, the opposite-'face ofthe sheet having shallow recesses extending therein opposite saidcorrugations, and

spaceds'core line's on the corrugated face of thesheetextending."transversely of the corrugations,

"thespa'ces' between said corrugations being not 5 less inwidthth'anthecorrugations.

EUGENE L. PERRY.

' Refcrences -Gited in the file of this patent UNITED STATES PATENTS

